The temporary shaping of hairstyles for an extended period of time of up to several days generally requires the use of setting active substances. For this reason, hair treatment agents that are used to temporarily shape the hair play an important role. Corresponding agents for the temporary deformation usually contain synthetic polymers and/or waxes as the setting active substance. Agents for assisting in the temporary deformation of keratin-containing fibers may be provided as hair spray, hair wax, hair gel, or hair foam, for example.
The most important property of an agent for the temporary deformation of hair, also referred to below as a styling agent, is to provide the treated fibers with a preferably strong hold in the reshaped form, i.e., a shape that is imparted to the hair. This is also referred to as a strong hairstyle hold or a high degree of hold of the styling agent. The hairstyle hold is determined essentially by the type and quantity of the setting active substances used, although influence by the other components of the styling agent may also be provided.
Styling agents must meet numerous other requirements besides a high degree of hold. These may be roughly divided into properties on the hair, properties of the particular formulation, such as properties of sprayed aerosols, and properties relating to the use of the styling agent, particular importance being attached to the properties on the hair. Mentioned in particular are moisture resistance, low tack, and a balanced conditioning effect. In addition, a styling agent should preferably be universally usable for all types of hair and be mild on the hair and skin.
In order to meet the various requirements, a number of synthetic polymers used in styling agents have already been developed as setting active substances. These polymers may be divided into cationic, anionic, nonionic, and amphoteric setting polymers.
Hair-setting agents based on copolymers of styrene with (meth)acrylic acid and/or the esters thereof are described in International Patent application WO 2012/168035 A1.
Hair sprays based on copolymers of N-tert-butylacrylamide, acrylic acid, and ethyl acrylate are described in German Patent application DE 10 2004 040 172 A1, among other publications.
Not every polymer, and not every polymer mixture, is basically suited for producing hair styling agents. This is particularly true for hair sprays, in which, for example, the viscosity and thus also the spray characteristics are influenced by the polymer and the quantity of polymer used.
Although suitable polymers and polymer combinations have been developed some time ago for use in the area of temporary hair deformation, the results achieved thus far still leave room for improvements, in particular with regard to the storage stability, the applicability, and the degree of hold of these agents. In particular, currently available styling agents are in need of further improvement, since a good combination of the degree of hold and the long-term hold (high humidity curl retention) is not always sufficiently ensured.